SIP 180 Ringing vs 502 Bad Gateway
SIP 180 (Ringing) is a 1xx Provisional response, while 502 (Bad Gateway) is a 5xx Server Failure response. 180 indicates that the UA receiving the INVITE is trying to alert the user. This response is used to initiate local ringback tone at the caller's end. In contrast, 502 means that the server, acting as a gateway or proxy, received an invalid response from a downstream server it accessed in attempting to fulfill the request.
설명
The UA receiving the INVITE is trying to alert the user. This response is used to initiate local ringback tone at the caller's end.
이 코드를 보게 되는 경우
During call setup when the callee's phone is ringing. You should hear a ringback tone after receiving this response.
해결 방법
No fix needed — the callee's device is ringing. If the call never connects after ringing, check the callee's device or call forwarding settings.
설명
The server, acting as a gateway or proxy, received an invalid response from a downstream server it accessed in attempting to fulfill the request.
이 코드를 보게 되는 경우
When a SIP proxy receives a malformed or invalid response from the next-hop server. Common in interop scenarios between different vendors.
해결 방법
Check the downstream server's health and configuration. Verify SIP message formatting between the two servers. Review network connectivity.
주요 차이점
180 is a 1xx Provisional response, while 502 is a 5xx Server Failure response.
SIP 180: The UA receiving the INVITE is trying to alert the user. This response is used to initiate local ringback tone at the caller's end.
SIP 502: The server, acting as a gateway or proxy, received an invalid response from a downstream server it accessed in attempting to fulfill the request.
You encounter 180 when during call setup when the callee's phone is ringing. You should hear a ringback tone after receiving this response.
You encounter 502 when when a SIP proxy receives a malformed or invalid response from the next-hop server. Common in interop scenarios between different vendors.
언제 어떤 것을 사용할지
For 180 (Ringing): No fix needed — the callee's device is ringing. If the call never connects after ringing, check the callee's device or call forwarding settings. For 502 (Bad Gateway): Check the downstream server's health and configuration. Verify SIP message formatting between the two servers. Review network connectivity.